Molecular Mechanisms of Cell Adhesion

节目概要 这项最大化研究者研究奖（MIRA）的建议直接关系到长期的 国家普通医学科学研究所（NIGMS）的计划。我们的实验室连续收到 自2004年以来，NIGMS的资助使我们能够在理解 相邻细胞之间的动态接触机制（粘附连接），以及 细胞和细胞外基质（粘着斑结构）。这些细胞连接，除了保持 动物细胞在一起，传递信号并控制施加在细胞上的压力。 在过去的16年里，我们为理解 ·细胞-细胞连接如何连接组织中的细胞以调节组织稳态，这对于 提供上皮的组织屏障以及细胞迁移和增殖;以及 ·细胞连接如何启动和维持细胞粘附，同时调节底层细胞的组织 通过建立细胞信号传导和基因转录调控中心来调节肌动蛋白细胞骨架。 这些进程是高度动态的，受到严格的管制。我们的实验室致力于定义 这些细胞连接的关键调节机制，我们在活细胞中进行了生物化学研究。我们 新技术的发展加速了我们的发现， 生物学的障碍，停滞不前的领域，适用于许多其他结构生物学研究。 我们发现了talin如何激活黏着斑蛋白，两种普遍表达的肌动蛋白结合蛋白， 局部粘连，从而抑制细胞迁移。我们的高分辨率黏着斑蛋白晶体结构， 我们在生物化学和活细胞中证实，显示了自抑制分子内相互作用， 因此，它可以抑制黏着斑蛋白，从而阻止黏着斑蛋白与肌动蛋白细胞骨架结合。 另一方面，我们的高分辨率晶体结构的α-连环蛋白，一个关键的调解人的细胞间 粘附，揭示了其四级结构在细胞-细胞粘附和细胞粘附中发挥的机械作用。 形成与肌动蛋白细胞骨架的动态连接。重要的是，我们的发现导致了机械- 细胞间和细胞间基质连接的转导研究，细胞如何感知和传递力。 最近，我们发现脂质如何与黏着斑蛋白、其心脏亚型后黏着斑蛋白和塔林蛋白结合， 调节粘着斑转换。这些知识和专业知识是进一步发现的基础 这将另外集中在质膜在细胞粘附中所起的研究不足的作用。 从长远来看，我们希望通过获得一个近原子的细胞粘附， “合成”细胞结的结构。细胞连接的调节和失调是 许多生物过程，如发育和癌症，因此我们提出的研究 既有基本的意义，也有潜在的翻译意义。

Program Summary This Maximizing Investigators’ Research Award (MIRA) proposal is directly relevant to the long-range plans of the National Institute of General Medical Sciences (NIGMS). Our laboratory received continuous NIGMS funding since 2004 that allowed us to make substantial advances in our understanding of the mechanisms of the dynamic contacts between neighboring cells (adherens junctions), as well as between cells and the extracellular matrix (focal adhesions structures). These cell junctions, in addition of holding animal cells together, communicate signals and control the stress placed upon cells. Over the past 16 years, we contributed important mechanistic discoveries towards an understanding of · how the cell-cell junctions connect cells in tissues to regulate tissue homeostasis that are crucial to provide the tissue barrier of epithelia, as well as cell migration and proliferation; and · how cell junctions initiate and maintain cell adhesion while regulating the organization of the underlying actin cytoskeleton by establishing a center for cell signaling and gene transcript regulation. Such processes are highly dynamic and tightly regulated. Our laboratory focused on defining the activation mechanisms of key regulators of these cell junctions that we studied biochemically and in live cells. Our discoveries were accelerated by our development of new techniques that overcame significant structural biology hurdles that stalled the field and that are applicable to many other structural biology studies. We discovered how talin activates vinculin, two ubiquitously expressed, actin-binding proteins, to stabilizes focal adhesions and thereby suppressing cell migration. Our high-resolution vinculin crystal structures, that we confirmed biochemically and in live cells, showed the auto-inhibitory intramolecular interactions that inactivate vinculin and thereby prevent vinculin from binding to the actin cytoskeleton. On the other hand, our high-resolution crystal structures of a-catenin, a crucial mediator of intercellular adhesions, revealed the mechanistic roles that its quaternary structures play in cell-cell adhesion and in the formation of the dynamic link to the actin cytoskeleton. Significantly, our discoveries led to mechano- transduction studies of cell-cell and cell-matrix junctions on how cells sense and transmit forces. More recently, we discovered how lipid binding to vinculin, to its cardiac isoform metavinculin, and to talin regulates focal adhesion turnover. This knowledge and expertise are the foundation for further discoveries that will additionally focus on the understudied role that the plasma membrane plays in cell adhesion. In the long run, we hope to gain a complete understanding of cell adhesion by attaining a near atomic structure of a “synthetic” cell junction. The regulation and dysregulation of cell junctions are fundamental to many biological processes such as development and cancer, and our proposed studies have therefore both basic and potentially translational significance.